function myVue(){
    const obj = {
        name:"obj",
        _msg:"hello",
        el: document.querySelector(".box"),
        elTxt: document.querySelector(".box").innerHTML,
        get msg(){
            console.log("msg被访问了");
            this.el.innerHTML = this.elTxt.replace("{{ msg }}", this._msg);
            return this._msg;
        },
        set msg(v){
            console.log("msg被修改了，要改成：", v);
            this.el.innerHTML = this.elTxt.replace("{{ msg }}", v);
            this._msg = v;
        }
    }
    obj.msg;
    return obj;
}